ABYC Air Conditioning & Refrigeration Certification Exam Review: Questions & Answers: Guaranteed A+ Score Guide

What is likely when low suction and discharge pressure are found, but high superheat and partial frosting on the evaporator unit are found? (Ans- System is undercharged A customer complains that the cabin is too cold and yet the A/C system is running all the time. What is likely wrong? (Ans- Failed thermostat What is the minimum pull-test requirement for friction-type electrical connectors? (Ans- 6 lbs for 1 minute What is the typical pressure and temperature of refrigerant on either side of the metering valve? (AnsHigh-side: 225 PSI, 110 degrees F Low-side: 70 PSI, 40 degrees F Are the contacts in a start relay (potential relay) normally open or closed when the system is off? (Ans- Normally closed (to connect the start capacitor at startup)runaway condition when insufficient airflow over the evaporator coil cases refrigerant temperature to drop below the refrigerant freezing point, causing ice to form on the coil, further reducing temperature and causing even less refrigerant to vaporize into gas form, eventually resulting in non-compressible liquid ingestion into compressor and possible damage. (Ans- liquid slugging The temperature at which the removal of any heat will begin a change of state from vapor to liquid (Ans- Condensation point The portion of a refrigeration system where the compression and condensation of refrigerant is accomplished. AKA "the high side" (Ans- Condensing unit Transfer of heat from molecule to molecule within a substance (Ans- Conduction Transfer of heat by moving fluid or air (Ans- ConvectionElectromagnetic actuated relay, usually referring to the relay which closes the circuit to the compressor. (Ans- Contactor Resistance heater in parallel with cooling circuit used to shorten the OFF cycle by adding heat when compressor is off. (Ans- Cooling anticipator